From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752782Ab3FYUCX (ORCPT ); Tue, 25 Jun 2013 16:02:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37200 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751946Ab3FYUCW (ORCPT ); Tue, 25 Jun 2013 16:02:22 -0400 Date: Tue, 25 Jun 2013 21:57:59 +0200 From: Oleg Nesterov To: Andrew Morton Cc: Al Viro , Denys Vlasenko , Eric Wong , Jason Baron , linux-kernel@vger.kernel.org Subject: [PATCH 2/2] signals: eventpoll: set ->saved_sigmask at the start Message-ID: <20130625195759.GA15252@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130625195738.GA15231@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org task_struct->saved_sigmask has no meaning unless we return with set_restore_sigmask() and nobody except current can use it. This means that sys_epoll_pwait() doesn't need to save ->blocked into the local var and then memcopy it into ->saved_sigmask, we can simply set ->saved_sigmask right before set_current_blocked(). Signed-off-by: Oleg Nesterov --- fs/eventpoll.c | 34 +++++++++++++++------------------- 1 files changed, 15 insertions(+), 19 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 0f0f736..2ea3584 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1964,23 +1964,23 @@ SYSCALL_DEFINE6(epoll_pwait, int, epfd, struct epoll_event __user *, events, size_t, sigsetsize) { int error; - sigset_t ksigmask, sigsaved; - /* * If the caller wants a certain signal mask to be set during the wait, * we apply it here. */ if (sigmask) { + sigset_t ksigmask; + if (sigsetsize != sizeof(sigset_t)) return -EINVAL; if (copy_from_user(&ksigmask, sigmask, sizeof(ksigmask))) return -EFAULT; - sigsaved = current->blocked; + + current->saved_sigmask = current->blocked; set_current_blocked(&ksigmask); } error = sys_epoll_wait(epfd, events, maxevents, timeout); - /* * If we changed the signal mask, we need to restore the original one. * In case we've got a signal while waiting, we do not restore the @@ -1988,12 +1988,10 @@ SYSCALL_DEFINE6(epoll_pwait, int, epfd, struct epoll_event __user *, events, * the way back to userspace, before the signal mask is restored. */ if (sigmask) { - if (error == -EINTR) { - memcpy(¤t->saved_sigmask, &sigsaved, - sizeof(sigsaved)); + if (error == -EINTR) set_restore_sigmask(); - } else - set_current_blocked(&sigsaved); + else + __set_current_blocked(¤t->saved_sigmask); } return error; @@ -2007,25 +2005,25 @@ COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd, compat_size_t, sigsetsize) { long err; - compat_sigset_t csigmask; - sigset_t ksigmask, sigsaved; - /* * If the caller wants a certain signal mask to be set during the wait, * we apply it here. */ if (sigmask) { + compat_sigset_t csigmask; + sigset_t ksigmask; + if (sigsetsize != sizeof(compat_sigset_t)) return -EINVAL; if (copy_from_user(&csigmask, sigmask, sizeof(csigmask))) return -EFAULT; sigset_from_compat(&ksigmask, &csigmask); - sigsaved = current->blocked; + + current->saved_sigmask = current->blocked; set_current_blocked(&ksigmask); } err = sys_epoll_wait(epfd, events, maxevents, timeout); - /* * If we changed the signal mask, we need to restore the original one. * In case we've got a signal while waiting, we do not restore the @@ -2033,12 +2031,10 @@ COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd, * the way back to userspace, before the signal mask is restored. */ if (sigmask) { - if (err == -EINTR) { - memcpy(¤t->saved_sigmask, &sigsaved, - sizeof(sigsaved)); + if (err == -EINTR) set_restore_sigmask(); - } else - set_current_blocked(&sigsaved); + else + __set_current_blocked(¤t->saved_sigmask); } return err; -- 1.5.5.1